Chris Grayling knocked cyclist off bike outside Parliament
Transport Secretary Chris Grayling knocked a cyclist off his bike outside Parliament in what his spokesman said was an "unfortunate accident".
Footage published by the Guardian showed Jaiqi Liu falling off after Mr Grayling opened his ministerial car's door as he passed by.
A spokesman said Mr Grayling went to check the cyclist was fine and apologised for what had happened.
The two are then seen to shake hands, following the incident on 12 October.
The footage has only emerged now after Laurence de Hoest, who was cycling behind Mr Liu and wearing a helmet camera, decided to publicise it after a story in Cycling Weekly reported Mr Grayling saying cycle lanes "cause too much of a problem for road users" in London.
Mr Grayling's car was stationary in traffic outside the Palace of Westminster when Mr Liu passed it on the inside.
The accident happened on a busy road heavily used by cyclists, about 20 metres before a cycle lane is restored.
Mr Liu said he had informed the police to ensure the accident was logged but did not expect it to be investigated. He did not not know who Mr Grayling was at the time.
His bike sustained damage to its wheel, brakes and lights.
A Labour MP has made a complaint to the Met Police, asking it to investigate whether Mr Grayling had broken the law by "injuring or endangering" someone through his actions.
Ian Austin also said the police should investigate whether the fact Mr Grayling did not provide his details to Mr Liu or notify the authorities constituted an offence.
Asked whether he knew it was the transport secretary who was involved, the cyclist who filmed the incident, Mr de Hoest, told BBC Radio 2's Jeremy Vine show: "Not at the time, it was only a few days later that I recognised it was Mr Grayling.
"I only sent the Guardian after his article in Cycling Weekly when he talks about ...cycle lanes taking up space for motorists and that didn't really sit comfortably with me, so I sent them the footage."
He said it had been "quite a forceful impact" and Mr Liu had been "quite shaken up" at the time.
But there was some disagreement on the show about whether Mr Grayling, or Mr Liu, had been in the wrong. Martin Key, campaigns manager for British Cycling, pointed to the Road Vehicles Regulations 1986 and Rule 239 of the Highway Code which states: "You must ensure you do not hit anyone when you open your door".
He added: "I believe that it is a very, very clear case that the transport minister was in the wrong."
He added: "Cycle lanes are on the inside of traffic, there's a cycle lane just up ahead where the transport minister knocks the cyclist off his bike and that cycle lane is on the left hand side, so the road infrastructure is asking us to be on the left."
But motoring journalist Steve Berry told the programme: "Why are you saying that he knocked the cyclist off his bike? ... That man cycled into the door of a car that was being opened so somebody could step onto the pavement."
"Motorcyclists would never dream of undertaking on the left hand side because ... somebody is going to open a car door and you are going to be knocked off.
"The transport secretary is clearly on the back seat of that vehicle. How on earth is he supposed to use the rear view mirror which is set up for the driver, who is sat on the other side and on the front seat?"
A spokesman for Mr Grayling, who has been transport secretary since July, said: "Mr Grayling got out of the car, checked the cyclist was OK and waited until he was back on his feet. Mr Grayling spoke to the cyclist and apologised.
"They shook hands before he left."